Papers by Tohid N.Borhani
Chemical Engineering Science
Energy Conversion and Management
Chemical Engineering Science
Clean Energy
Combined cooling, heating and power (CCHP) systems are characterized by a substantially higher en... more Combined cooling, heating and power (CCHP) systems are characterized by a substantially higher energy-utilization efficiency compared to standalone systems. In this study, an integrated system comprising a solid-oxide fuel cell (SOFC), hot-water storage tank (HWST) and absorption refrigeration (AR) cycle is considered. The SOFC model was developed in Aspen Plus®. It was used to determine the thermodynamic properties of the exhaust gas that was then used to provide heat for the HWST and to drive the AR cycle. Thermodynamic models for the AR cycles were developed in Engineering Equation Solver, considering LiBr–H2O and NH3–H2O as working fluids. The sensitivity analysis of a number of SOFC output parameters has been carried out. The most optimal case was characterized with the coefficient of performance (COP) and CCHP efficiency of 0.806 and 85.2% for the LiBr–H2O system, and 0.649 and 83.6% for the NH3–H2O system, respectively. Under such optimal operating conditions, the SOFC was ch...
Five major operations for the conversion of lignocellulosic biomasses into bioethanol are pre-tre... more Five major operations for the conversion of lignocellulosic biomasses into bioethanol are pre-treatment, detoxification, hydrolysis, fermentation, and distillation. The fermentation process is a significant biological step to transform lignocellulose into biofuel. The interactions of biochemical networks and their uncertainty and nonlinearity that occur during fermentation processes are major problems for experts developing accurate bioprocess models. In this study, mechanical processing and pre-treatment on the palm trunk were done before fermentation. Analysis was performed on the fresh palm sap and the fermented sap to determine the composition. The analysis for total sugar content was done using high-performance liquid chromatography (HPLC) and the percentage of alcohols by volume was determined using gas chromatography (GC). A model was also developed for the fermentation process based on the Adaptive-Network-Fuzzy Inference System (ANFIS) combined with particle swarm optimization (PSO) to predict bioethanol production in biomass fermentation of oil palm trunk sap. The model was used to find the best experimental conditions to achieve the maximum bioethanol concentration. Graphical sensitivity analysis techniques were also used to identify the most effective parameters in the bioethanol process.
In advanced oxidation processes (AOPs), the aqueous hydroxyl radical (HOradical dot) acts as a st... more In advanced oxidation processes (AOPs), the aqueous hydroxyl radical (HOradical dot) acts as a strong oxidant to react with organic contaminants. The hydroxyl radical rate constant (kHOradical dot) is important for evaluating and modelling of the AOPs. In this study, quantitative structure-property relationship (QSPR) method is applied to model the hydroxyl radical rate constant for a diverse dataset of 457 water contaminants from 27 various chemical classes. The constricted binary particle swarm optimization and multiple-linear regression (BPSO-MLR) are used to obtain the best model with eight theoretical descriptors. An optimized feed forward neural network (FFNN) is developed to investigate the complex performance of the selected molecular parameters with kHOradical dot. Although the FFNN prediction results are more accurate than those obtained using BPSO-MLR, the application of the latter is much more convenient. Various internal and external validation techniques indicate that the obtained models could predict the logarithmic hydroxyl radical rate constants of a large number of water contaminants with less than 4% absolute relative error. Finally, the above-mentioned proposed models are compared to those reported earlier and the structural factors contributing to the AOP degradation efficiency are discussed.
Permeability modification of porous media using microorganisms to enhance oil recovery has become... more Permeability modification of porous media using microorganisms to enhance oil recovery has become a useful and feasible technology for oil production from watered-out oil fields. The purpose of these experimental experiences was to determine capability of microorganisms to reduction of the permeable zone. A sand packed column and a two dimensional glass micromodel were used to demonstrate the effectiveness of in situ profile modification with spores. In both cases, the apparatus conditions were chosen to isolate the plugging mechanisms just associated with exopolymer production and eliminate any impact of cell growth to profile modification. Bacillus Licheniformis (an exopolymer producing bacterium) was employed in this set of experiments. Temperature, salinity, and incubation times were three different variables that were studied in these investigations. The results show that B. licheniformis is proper to make plugging to profile modification in salty reservoir with temperatures close to 40ºC. In Addition it was demonstrated that this bacteria can reduce the permeability of reservoir as incubation time is increasing. Likewise, the visual results of glass micromodel experiments were compatible to sand packed surveys. Hence, B. licheniformis is suggested for microbial enhanced oil recovery (MEOR) in highly saline sand stone reservoir with about 40ºC temperature value.
A two dimensionally Eulerian- Eulerian multiphase flow model coupled with a population balance mo... more A two dimensionally Eulerian- Eulerian multiphase flow model coupled with a population balance modeling (CFD-PBM) simulation was implemented to investigate the fluidization structure in an industrial scale gas phase polymerization reactor (FBR). Direct quadrature method of moments (DQMOM) was employed in this model to solve the PBM. Two cases including perforated distributor and complete sparger have been applied to examine the flow structure through the bed. A simulation of the reactor with perforated distributor was performed first to validate and evaluate the impact of distributor's characteristics on the fluidization behaviors. The predicted results were in good agreement with the industrial data in terms of pressure drop and bed height. The results showed that different heterogeneous flow patterns created in a perforated distributor, due to more kinetic energy and jet formation above the distributor. A dead zone is expected to be formed near the corners of perorated distributor. In addition, the cluster formation is expected to be decreased in comparison with the complete sparger plate distributor. Furthermore, the results predicted bigger bubble diameter in case of perforated distributor by using image processing technique. The information obtained from this study could be important to assure efficient industrial operations of FBRs.
A 2D computational fluid dynamics (Eulerian–Eulerian) multiphase flowmodel coupled with a populatio... more A 2D computational fluid dynamics (Eulerian–Eulerian) multiphase flowmodel coupled with a population balance model (CFD-PBM) was implemented to investigate the fluidization structure in terms of entrance region in an industrial-scale gas phase fluidized bed reactor. The simulation results were compared with the industrial data, and good agreement was observed. Two cases including perforated distributor and complete sparger were applied to examine the flow structure through the bed. The parametric sensitivity analysis of time step, number of node, drag coefficient, and specularity coefficient was carried out. It was found that the results were more sensitive to the drag model. The results showed that the entrance configuration has significant effect on the flow structure. While the dead zones are created in both corners of the distributors, the perforated distributor generates more startup bubbles, heterogeneous flow field, and better gas–solid interaction above the entrance region due to jet formation.
Fluidized bed polymerization reactor Direct quadrature method of moments a b s t r a c t In an in... more Fluidized bed polymerization reactor Direct quadrature method of moments a b s t r a c t In an industrial fluidized bed polymerization reactor, particle size distribution (PSD) plays a significant role in the reactor efficiency evaluation. The computational fluid dynamic (CFD) models coupled with population balance model (CFD-PBM) have been extensively employed to highlight its potential to analyze the industrial-scale gas phase polymerization reactor (FBRs) utilizing ANSYS Fluent software. The predicted results reveal an acceptable agreement with the observed industrial data in terms of pressure drop and bed height. Courant number independent study has been carried out to record the mesh and time step independent results for large scale FBRs. Furthermore, the minimum fluidization velocity (U mf ) and size-dependent particle growth rate have been assessed to emphasize the impact of PSD along the reactor. The results show transient regime in the case of minimum fluidization velocity. The simulation results signify that in order to improve the polymerization yield, the amount of gas velocity can be increased without change in the fluidization regime, i.e. segregation. Hence, the 2D CFD-PBM/DQMOM coupled model can be used as a reliable tool for analyzing and improving the design and operation of the gas phase polymerization FBRs. (Mohd.K.Abd. Hamid).
This study presents a rate-based model of an absorber packed column for simultaneous absorptions ... more This study presents a rate-based model of an absorber packed column for simultaneous absorptions of acid gases into methyldiethanolamine (MDEA) aqueous solution. The model is in good agreement with experimental data. The parametric study showed that the concentration of acid gases in the sweet gas stream increases by decrease in the specific surface area of packing. The peak of selectivity factor decreases with the increase in the mole ratio of CO2/H2S in the gas feed along the packed column. The sensitivity analysis reveals that selecting the accurate correlations of the gas-side mass transfer coefficient and specific surface area is vital.
Chemical Engineering Research and Design, 2015
Mixing and segregation a b s t r a c t
The potassium carbonate (PC) solution is an important chemical solvent to reduce CO2 emissions du... more The potassium carbonate (PC) solution is an important chemical solvent to reduce CO2 emissions due to its advantages of low cost, little toxicity, ease of regeneration, slow corrosiveness, low degradation, and its high stability as well as CO2 absorption capacity. As a result, the PC process has been applied in more than 700 plants worldwide for CO2 and hydrogen sulphide removal from streams like ammonia synthesis gas, crude hydrogen, natural gas, and town gas. This paper provides a state-of-the-art review on the research works on CO2 capture using the PC solution. The studies related to the PC solution comprise three main areas: process, thermodynamics, and kinetics. Important experimental studies as well as modeling and simulation studies are reviewed. Future research directions on CO2 absorption by aqueous PC solution are highlighted and discussed.
One of the key concerns of the purification section of purified terephthalic acid (PTA) productio... more One of the key concerns of the purification section of purified terephthalic acid (PTA) production plant is the deactivation of palladium supported on carbon (Pd/C) catalyst. In this work, the deactivation rate model of 0.5 wt.% Pd/C catalyst has been developed considering temperature, active surface area, and residual catalytic activity. Moreover, the optimal operating conditions of the industrial hydropurification process has been investigated. The results show that PTA production rate (PPR) can be improved by 5.4 percent through 18 percent increase in hydrogen flowrate. Furthermore, PPR can be increased by 7.6 percent via the temperature rise in the reaction mixture. The optimization results further reveal that PPR can be enhanced by 17.3 percent by improving the feed concentration under the normal operation by means of limiting the inlet 4-carboxybenzaldehyde concentration. The research findings can be applied in the actual working plant to enhance the efficiency of the hydropurification process.
The particle size distribution (PSD) has a significant influence on the performance of fluidized ... more The particle size distribution (PSD) has a significant influence on the performance of fluidized bed reactors, as uneven distribution usually results from segregation and mixing tendencies. The objective of this paper is to study the segregation of wide range of particle size distribution in an industrial gas phase polymerization reactor by means of a CFD–PBM coupled model, where the direct quadrature method of moments (DQMOM) was implemented to solve the population balance model. It was shown that the model is able to satisfactorily predict the available operational data in terms of pressure drop and bed height. Model sensitivities of discretization scheme, maximum solid packing and fluidization/de-fluidization were also studied. The transient CFD–PBM/DQMOM coupled model is then utilized extensively to analyze minimum fluidization velocity, fluidization behavior and segregation phenomena at different velocities. The results suggested that third-order MUSCL discretization scheme, maximum solid packing value which is 0.01 higher than specific solid volume fraction and also fluidization process were mathematically and physically consistent with real observation. In addition, the segregation is strongly affected at minimum fluidization velocity range of particles. The PSD becomes well-mixed at high gas velocity while the quasi-layer inversion was predicted in low gas velocity.
In this study, the equilibrium and non-equilibrium models for CO2 absorption from natural gas str... more In this study, the equilibrium and non-equilibrium models for CO2 absorption from natural gas stream by DEA-promoted potassium carbonate solution in a tray column were developed and compared with each other. The Electrolyte NRTL thermodynamic model was utilized to calculate the activity coefficient in the liquid phase, and the SRK equation of state was used for the gas phase. The non-equilibrium model was based on the two-film theory, and the effect of film discretization was examined. The equilibrium model was based on the theoretical number of stages combined with the concept of Murphree efficiency from 0.1 to 0.3 for three stages in the lower section of the column and 0.4 from stage 4 onwards. A thermodynamic study was performed to describe the equilibrium behavior of the solvent. All the necessary reactions in the liquid phase were considered in all simulations. The models were validated by comparing the obtained results with the published experimental data. Results of absorber column simulation show that the non-equilibrium model gives a better prediction of the temperature and concentration profiles as compared to the equilibrium model.
Energy conversion system’s performance depends on exergy analysis and entropy generation minimiza... more Energy conversion system’s performance depends on exergy analysis and entropy generation minimization. A new simple four-parameter equation is presented in this paper to predict the standard state absolute entropy of real gases (SSTD). The model development and validation were accomplished using the Linear Genetic Programming (LGP) method and a comprehensive dataset of 1727 widely-used materials. The proposed model was compared with the results obtained using a three-layer feed forward neural network model (FFNN model). The root-mean-square error (RMSE) and the coefficient of determination (r2) of the all data obtained for the LGP model were 52.24 J/(mole.K) and 0.8851. Several statistical assessments were used to evaluate the predictive power of the model. In addition, this study provides an appropriate understanding of the most important molecular variables for exergy analysis. Compared to the LGP based model, the application of FFNN improved the r2 to 0.9135. The developed model is useful in the design of materials to achieve a desired entropy value.
Uploads
Papers by Tohid N.Borhani
در چاپ پنجم این کتاب کیفیت کتاب چه از نظر ترجمه و چه از نظر شکل ظاهری به طور قابل توجهی افزایش یافته است.
ترجمه: توحید نژاد غفار برهانی، محسن رضایی منش، فرهاد جدیدی
انتشارات: ناشر- مولف ([email protected])
تعداد صفحه: 500
قیمت: 35000 تومان
قطع: وزیری
شابک: 5-8441-04-600-978
پخش کتاب پاسارگاد: 09122377622
66977076
این کتاب شامل بررسیهای بهروز مختلف خواص سنگ و سیال با استفاده از عبارات ریاضی و روشهای مختلف اندازهگیری آزمایشگاهی و به منظور بیان روابط و تاثیرات متقابل بین خواص مختلف، میباشد. این کتاب بر دستیابی به دادههای صحیح و قابل اطمینان، توصیف روشهای مغزهگیری و نمونهبرداری، مسائل مرتبط با نگهداری نمونهها برای انجام تحلیلهای مغزه، و مطالعات PVT که شامل نمونهبرداری از سیال مخزن، تعیین اعتبار نمونههای جمعآوری شده، تحلیلهای ترکیب درصد، و تقطیر در نقطه جوش حقیقی میباشد، تمرکز نموده است. همچنین این کتاب توجه خواننده را به تحلیلهای مغزه و رفتار فازی با استفاده از آزمونهای آزمایشگاهی، و محاسباتی به منظور تعیین محدودهی وسیعی از ویژگیها، نظیر محاسبات تعادل بخار- مایع (VLE) با استفاده از معادلات حالت، معطوف میکند.
خلاصهای از محتویات کتاب:
• مراجع بهروز موجود در مقالات، نمودارهای گرافیکی زیاد، مثالهای عملی به منظور بیان مفاهیم مهّم، و مثالهای حلشده در هر فصل.
• بیان دستگاههای آزمایشگاهی با جزییات آنها، که از آن میتوان برای طراحی دستگاههایی به منظور اندازهگیری خواص سنگ و سیال استفاده نمود.
• توصیف قانون دارسی، فرایند آشام، فرایند تخلیه، تراوایی نسبی در حالت پایا و در حالت ناپایا، و توانهای Corey.
• بررسی اشباع آب تحویلناپذیر و ترشوندگی از دیدگاه سازند مخازن نفتی و مطالعات آزمایشگاهی.
• بررسی رفتار فازی سامانههای چند سازندهای خالص و معین، و پنج سیال مخزن نفتی - نفت سیاه، نفت فرار، میعانات گازی، گاز تر، و گاز خشک – از جنبههای فرایند تولید و فرایندهای سطحی.
• توصیف آزمون انبساط ترکیب ثابت، آزمون کاهش (تخلیه) حجم ثابت، تفکیک تفاضلی، تفکیک مرکب، و آزمونهای جداساز.
• مباحثی در مورد جنبههای تئوری و عملی، که باعث تسهیل حل مسائل واقعی و موجود در مهندسی نفت میشود.